[AC Question]

So I was updating my galaxy s5 from kit kat to marshmallow through the Samsung Kies 3 application and it did the update but when it finished it is just stuck on the boot screen and at the top it says "Recovery booting. . . . ." and now nothing is happening it is just stuck on the screen. I have never rooted the phone or installed any custom ROMs so I don't know why I have this problem. I honestly have no idea what to do now, so if anyone know how to fix this, please tell me.

[Rukbat]

It can take hours to recover from a bad ROM flash, so leave it until tomorrow. If it still doesn't work, you'll have to reflash the ROM (see [Samsung] How to flash Stock ROM via ODIN) (you'll lose all your data, pictures, downloaded apps, etc., so see Backing up an Android Device), or take it to the carrier's store and ask if they can reflash the update.